Hippos didn’t rush out of Central Europe as the ice advanced. New tests on ancient bones reveal these huge semi-aquatic animals still wandered Germany’s Upper Rhine Valley between about 47,000 and 31,000 years ago. Deep into the last ice age.
A global team led by scientists from the University of Potsdam and the Reiss-Engelhorn-Museen in Mannheim, working closely with the Curt-Engelhorn-Zentrum Archäometrie, shared the discovery in Current Biology.
Rewinding the Exit Clock
Standard thinking had common hippos (Hippopotamus amphibius) vanishing from Europe about 115,000 years ago, once the mild interglacial ended and harsh cold set in. This latest research, however, which involved specialists from ETH Zurich and other institutions, shows that a small group of H. amphibius held on in southwestern Germany for tens of thousands of years longer, enduring the Weichselian glaciation’s occasional warmer phases.
The Upper Rhine Graben acts like a sealed vault. Rivers stacked gravel and sand over millennia, perfectly preserving animal remains. Dr. Ronny Friedrich–the age-dating expert at the Curt-Engelhorn-Zentrum Archäometrie–points out that many bones stayed in remarkably good shape, yielding samples ideal for testing even after such a vast stretch of time.
DNA and Carbon Say the Same Thing
The researchers used both ancient DNA sequencing and radiocarbon dating. Genetic results matched these Ice Age hippos to the same species still found in African waterways today. The carbon dates placed them in a short temperate window that kept the area livable long enough for hippos to persist.
Closer genome inspection exposed very low diversity, indicating the European population was small and cut off from relatives farther south. Fossils also place these heat-loving giants alongside mammoths and woolly rhinos, underlining how unusually mixed and diverse Ice Age habitats could be.
Time to Dust Off the Old Bones
Lead author Dr. Patrick Arnold stresses that hippos did not disappear from central Europe at the close of the last interglacial as long thought to be believed, so every fossil previously assigned to that era deserves fresh scrutiny.
Dr. Wilfried Rosendahl, director of the Reiss-Engelhorn-Museen and head of the Eiszeitfenster Oberrheingraben project, sees the ice age as far from uniform; local warm pockets created a patchwork environment. He views this finding as one fragment of a larger mosaic and urges similar re-examination of other warmth-dependent species once thought gone much earlier.
The study falls under the Eiszeitfenster Oberrheingraben initiative, backed by the Klaus Tschira Stiftung in Heidelberg. Teams continue sifting the Reis collection of Ice Age bones kept at the Mannheim museum, steadily reshaping our picture of Europe’s ancient wildlife, bone by bone.
Top Image: Hippopotami that thrive in present-day Africa once called Prehistoric Europe home. Source: Public Domain.
References:
University of Potsdam. “Hippos once roamed frozen Germany with mammoths.” ScienceDaily. ScienceDaily, 26 October 2025. www.sciencedaily.com/releases/2025/10/251026021740.htm
